Electrical installation assemblage and conductor clamp



Dec. 21 1926.

H. F. VAUGHN ET AL ELECTRICAL INSTAULATION ASSEMBLAGE AND CONDUCTORCLAMP Filed May 6, 1926 W W QM fifFVauykn Jifi. jv em z'nj Patented Dec.21, 1926.

UNITED STATES PATENT OFFICE.

HERMAN IE. VAUGHN AND RAYMOND R. TERPENING, OF SCHENECTAIDY, NEW YORK.

ELECTRICAL INSTALLATION ASSEMBLAGE AND CCNDUCTOR CLAMP.

Application filed May is,

In electrical construction work, when clamping conductors to switchboxes, outlet boxes, and other receptacles,-it is customary -to .passsaid conductors through relatlvely large openings in the receptacle andsecure them by means of a screw-operated clamp within the receptacle.The form of clamp heretofore employed leaves gaps'between'the conductorsand the edge. walls of the openings through which they pass, which gapsare contrary to regulations covering electrical installation, andconstitute a dangerous lire hazard. It is the principal object of ourinvention to provide a new .and improved electrical installationassemblagedncluding a clamp which is so constructed as'to close the gapsof the openings, heretofore left by the form of clamp previouslyemployed.

Another object of the invention 1s to provide a clamp which will notonly etfectlvely close the portion of the knockout hole not occupied bythe conductor armor, but whlch may be used to efiectlvely grlp and holdany of the several sizes of flexible metallic armored cables as. well asthe non-metallic sheathed cables. and the flexible tubingsnow 1n use.

Other objects are to provide a combined cable clamp andlmockout-hole-closure of almost universal application tothe standardswitch and outlet boxes, which may bemanufactured at small cost, whichmay be easily and quickly installed, and which W111 be strong and highlyeffective 1n use.

With the foregoing in view, the IIIVQIltlpD. resides in the novelsubject matter hereinafter described and, claimed, the descript on beingsupplemented by the accompanymg drawing.

showing the improved clamp in usefor securing two conductors to saldbox.

Figure 2 is a transverse 'sectlona'l new on line 2-2 of Fig. 1.

line 33ofFig.2.. v Figure 4 is a perspective view of the 1mprovedclamping member.

m 1n the drawing above briefly described,

Figure 1 is an elevation of aswitch box Figure 3 is an enlarged detailsection connecting the numeral 5 designates a receptacle which,

1926. Serial No. 107,189.

for the purposes of this specification, may be considered as any of thewell known cabinets, switch boxes, outlet boxes, or other enclosures orreceptacles commonly used in electrical installation. The termreceptacle'will hereinafter be used with this understanding in view. I

The receptacle 5 isformed with the usual continuous-walled openings orknockout holes 6 through which the conductors 7 and Q their protectingarmors 8 pass and in which they are held .by our improved clampingmember 9. The latter serves the double function of closing theunoccupied portions of the knockout holes and of holding one or 65 twoof the armored cables that enter the receptacle. This improved clampcomprises essentially a closing portion or plate shaped to slide againstthe inner wall of the receptacle, arched clamping portions rigid withthe plate at an angle thereto and braced by itso that they will securelygrip and hold either one or two conductors, and suitable means forholding these parts inoperative position.

In the present showing, the member 9 comprises two arched clampingportions 10 to engage the armors 8, said clamping por tions beingintegrall .connected by a con-- necting portion' 11 aving an opening 12which receives a clamping screw 13 suitably engaged with an opening inthe receptacle, this opening being in a wall of the receptacle at rightangles to the wall in which the openings 6 are formed. The member 9 is35 disposed adjacent the inner side of one wall of the receptacle 5 andits inner edge is preferably provided, in the clam-ping portions 10,with inwardly stamped lugs '14 to anti-slippingly engage the armors -8,regardless of the nature of the latter, that is, whether said armors beof flexible metal tubing, tubing formed from helically wrappedstripping, or tubing formed from. woven or other nonmetallic material.The outer edge of the member 9 is provided with an integral plate 15 ina plane at right angles to that of the portion 11, said plate beingadapted to slidably engage the inner side of the receptacle wall, asshown- In this 1 9 stamped metal construction illustrated the drawing,it willbe seen that the arched clamping portions 10 and the connectingportion 11 form a relatively long and narrow continuous flange along theedge of the plate 15 so that these parts brace or strengthen each otherto provide a strong clamp with the use of the minimum amount of metal;and at the same time the clamping portions 10 have sufficient bearing onthe cables or conductors to prevent the tilting of the plate 15 awayfrom the wall of the receptacle when i the clamping screw is tightened.The shape and size of the clamping portions 10 may of course be variedbut they project substantially at right angles from plate 15 and followthe contourof arched edges or seats in said plate 15. Thus, when theclamping member is moved rectilinearly to clamping position by the screw13, this plate covers the gaps which would otherwise exist between therelatively small conductor armors and the edges of the comparativelylarge openings 6. By closing these gaps, the assembly is broughtwellwithin the realm of standard requirements regarding electricalinstallation, and. the fire hazard is greatly reduced.

In the present showing, both conductors 8 pass through one end of thereceptacle 5 and are held by the single clamp 9, but one of these clampsmay if desired be provided at each end of the receptacle, in which case,one conductor could be located at one end and the other conductor at theother end of said receptacle,'only half of each clamp being theneffective. It is, of course, understood that the receptacle is providedwith knockouts, anyofwhich may be removed, according to the manner inwhich the conductors must be arranged.

In the standard switch and outlet boxes the knockouts are of one sizewhich is slightl v larger than the diameter of the largest size flexiblearmored cable; and it will be readily observed that the plate 15 is ofsuch size that when the smallest size cable is used or when the smallerflexible tubing or the nonmetallic sheathed-cable is used, the portionof the knockout hole not occupiedby the conductor or conduit will beeffectively closed against the possibility of sparks or flame leavingthe box through such hole. The one clamp is therefore usable with all ofthe sizes of these several kinds of cables or conductors now in generaluse; and it may be used in the smallest size of the standard switch boxwhere the interior space is limited. In actual use, it has been found inall of these different uses to be very effective in securely holding thecable or conduit without injury or short-circuiting as well as in safelyclosing the unoccupied-portions of the knockout .holes.

The device is exceptionally simple and 1nexpensive, may be easilymanufactured, may be applied or released with ease, and is generallyadvantageous. While it is intended primarily for use in connection withelectrical work, it might in some instances be used in other fields.

On account of existing advantages for the details disclosed, they arepreferably followed. Howeven within the scope of the invention asclaimed, variations may of course be made.

What is claimed is:

1. An electrical installation assemblage comprising an electricalreceptacle having two walls at an angle to each other, one of said wallshaving two openings to receive conductors while the other of said wallsis formed with a screw receiving opening whose axis is between the axesof said conductorreceiving openings, a plate contacting slidably withthe inner side of said one wall and having an edge disposed at the edgeport1ons of said conductor-receiving openings remote from said otherwall, said plate being provided with a lateral relatively long andnarrow flange along said edge projecting into the receptacle in spacedrelation with said other wall, said flange being provided with archedends to engage the conductors and having a screw-receiving openingbetween said arched ends and near said plate, this opening being alinedwith the aforesaid screw-receiving opening, and a headed screw 4 passingthrough said screw-receiving open- .1ng and having its head contactingwith the flange, said screw being threaded into the screw-receivinopening of said other wall and when tightened serving to draw theaforesaid plate and its flange rectilinearly toward said other wall toclamp the conductors in place, said plate then serving to close portionsof the conductor-receiving openings remote from said other Wall.

aforesaid plate contacting with the apertured receptacle wall, a screwmay be passed through said opening to secure the arched ends of theflange against conductors passing through the wall apertures, said platethen serving to close portions of the apertures unoccupied by theconductors.

3. A combined conductor clamp-and closure for the unoccupied portions ofconductor-receiving apertures in an electrical receptacle, com rising aplate having arched seats, arched 0 am ing portions projectin laterallyfrom said p ate at said seats an followin the contour thereof, and aortion artures, said late then servin to close g P P 8 having anopening, whereby upon sposal portions of the apertures unoccupied by theof the article within a. receptacle with the conductors. 10 plate inslidable contact with the apertured In testimony whereof we havehereunto wall thereof, a screw may be passed through aflixed our siatures.

said opening to clamp the arched flanges HE MAN F. VAUGHN.

against conductors passing through the wall 1 RAYMOND R. TERPENING.

